Electronic apparatuses that have a built-in Global Positioning System (GPS) receiver to measure an own position are becoming popular. Although the GPS receiver receives signals from the GPS satellites which go around the earth to measure the own position, in order to measure the position, signals received from at least equal to or greater than three GPS satellites are necessary. When the GPS receiver is located in an indoor site, the signals from the sufficient number of GPS satellites are not receivable, and thus the position measurement is difficult. Accordingly, since the GPS receiver is unable to measure the position even if executing a signal receiving operation for measuring the position, waste power is consumed. Hence, according to, for example, an electronic watch disclosed in Unexamined Japanese Patent Application Kokai Publication No. 2011-38988, the operation of a GPS receiver is controlled in accordance with the power generation amount by solar cells, thereby suppressing a waste signal receiving operation, and attempting a reduction of power consumption.
According to the electronic watch disclosed in the above Patent Literature, when the power generation amount by the solar cells is little, a determination is made such that such a clock is presently located in an indoor site, and the GPS receiver is controlled so as not to execute the signal receiving operation for measuring the position. In the night time, however, since the power generation amount is little even if such a clock is located in an outside site, the electronic watch mistakenly determines that such a clock is located in an indoor site, and an opportunity for receiving the GPS signal is missed although the position measurement is enabled in nature.